<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>

  <div id="app">
    姓：<input type="text" v-model="firstName"><br>
    名：<input type="text" v-model="lastName"><br>
    <p>姓名：{{ fullName }}</p>
    <button @click="changeName">修改姓名</button>
  </div>
  <script src="./vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        firstName: '刘',
        lastName: '备',
      },
      methods: {
        changeName() {
          this.fullName = '张飞'
        }
      },
      computed: {
        // 简写 -> 获取, 没有配置设置的逻辑
        // fullName () {
        //   return this.firstName + this.lastName
        // }

        // 完整写法 -> 获取，设置
        fullName: {
          get() {
            // (1) 当fullName计算属性，备货区求值，执行get（有缓存读缓存）
            // 会将返回值作为求值的结果
            return this.firstName + this.lastName
          },
          // (2) 当fullName计算属性，被修改赋值的时候，执行set
          // 修改的值，传递给set方法的实参
          set(value) {
            // console.log(value)
            // console.log(value.slice(0, 1));
            // console.log(value.slice(1));
            this.firstName = value.slice(0, 1)
            this.lastName = value.slice(1)
          }
        }
      },
    })
  </script>
</body>
</html>